Her sister Mary, a school teacher, was killed in an ambush by an IRA unit as she left Sunday morning Mass in south Belfast with her father, magistrate Tom Travers, in 1984. One of those convicted in relation to the attack, Mary McArdle, was appointed two years ago as a special adviser to Culture and Arts Minister Caral Ni Chuilin of Sinn Fein.

The appointment led to a private members' bill from hardline unionist Jim Allister which the SDLP failed to amend during a five-hour debate in the Assembly on Monday.

The SDLP had insisted an appeal mechanism and measures to make the legislation less open to legal challenge were essential if it was to support the bill.

As the Belfast Telegraph reported yesterday, the party then indicated it will use the petition mechanism with which Sinn Fein votes will effectively destroy Mr Allister's legislation.

Mrs Travers said she had never expected to have to "bang her head off a brick wall" with the SDLP "in a million years".

"I feel so disappointed, gutted – I have been punched in the stomach," she told the BBC NI Talkback programme.

The SDLP's Dominic Bradley said: "Victims must be protected but by legislation which is fair and just.

"For the SDLP, the acid test for dealing with the issue of special advisers has always been the rights of victims enshrined in the right legislation."